| Message ID | 20220222152045.484610-1-nathan@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] drm/stm: Avoid using val uninitialized in ltdc_set_ycbcr_config() | expand |
On 2/22/22 16:20, Nathan Chancellor wrote: > Clang warns: > > drivers/gpu/drm/stm/ltdc.c:625:2: warning: variable 'val' is used uninitialized whenever switch default is taken [-Wsometimes-uninitialized] > default: > ^~~~~~~ > drivers/gpu/drm/stm/ltdc.c:635:2: note: uninitialized use occurs here > val |= LxPCR_YCEN; > ^~~ > drivers/gpu/drm/stm/ltdc.c:600:9: note: initialize the variable 'val' to silence this warning > u32 val; > ^ > = 0 > 1 warning generated. > > Use a return instead of break in the default case to fix the warning. > Add an error message so that this return is not silent, which could hide > issues in the future. > > Fixes: 484e72d3146b ("drm/stm: ltdc: add support of ycbcr pixel formats") > Link: https://github.com/ClangBuiltLinux/linux/issues/1575 > Acked-by: Yannick Fertre <yannick.fertre@foss.st.com> > Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> > Reviewed-by: Raphael Gallais-Pou <raphael.gallais-pou@foss.st.com> > Signed-off-by: Nathan Chancellor <nathan@kernel.org> > --- > > v1 -> v2: https://lore.kernel.org/r/20220207165304.1046867-1-nathan@kernel.org/ > > * Use DRM_ERROR() instead of drm_err() (Philippe). Hi Nathan, Applied on drm-misc-next. Many thanks for your patch, Philippe :-) > > * Collect tags from v1, as nothing substantial has changed. > > drivers/gpu/drm/stm/ltdc.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/stm/ltdc.c b/drivers/gpu/drm/stm/ltdc.c > index 5eeb32c9c9ce..c9bc4ccb6d43 100644 > --- a/drivers/gpu/drm/stm/ltdc.c > +++ b/drivers/gpu/drm/stm/ltdc.c > @@ -624,7 +624,8 @@ static inline void ltdc_set_ycbcr_config(struct drm_plane *plane, u32 drm_pix_fm > break; > default: > /* RGB or not a YCbCr supported format */ > - break; > + DRM_ERROR("Unsupported pixel format: %u\n", drm_pix_fmt); > + return; > } > > /* Enable limited range */ > > base-commit: 542898c5aa5c6a3179dffb1d1606884a63f75fed
diff --git a/drivers/gpu/drm/stm/ltdc.c b/drivers/gpu/drm/stm/ltdc.c index 5eeb32c9c9ce..c9bc4ccb6d43 100644 --- a/drivers/gpu/drm/stm/ltdc.c +++ b/drivers/gpu/drm/stm/ltdc.c @@ -624,7 +624,8 @@ static inline void ltdc_set_ycbcr_config(struct drm_plane *plane, u32 drm_pix_fm break; default: /* RGB or not a YCbCr supported format */ - break; + DRM_ERROR("Unsupported pixel format: %u\n", drm_pix_fmt); + return; } /* Enable limited range */
Clang warns: drivers/gpu/drm/stm/ltdc.c:625:2: warning: variable 'val' is used uninitialized whenever switch default is taken [-Wsometimes-uninitialized] default: ^~~~~~~ drivers/gpu/drm/stm/ltdc.c:635:2: note: uninitialized use occurs here val |= LxPCR_YCEN; ^~~ drivers/gpu/drm/stm/ltdc.c:600:9: note: initialize the variable 'val' to silence this warning u32 val; ^ = 0 1 warning generated. Use a return instead of break in the default case to fix the warning. Add an error message so that this return is not silent, which could hide issues in the future. Fixes: 484e72d3146b ("drm/stm: ltdc: add support of ycbcr pixel formats") Link: https://github.com/ClangBuiltLinux/linux/issues/1575 Acked-by: Yannick Fertre <yannick.fertre@foss.st.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Raphael Gallais-Pou <raphael.gallais-pou@foss.st.com> Signed-off-by: Nathan Chancellor <nathan@kernel.org> --- v1 -> v2: https://lore.kernel.org/r/20220207165304.1046867-1-nathan@kernel.org/ * Use DRM_ERROR() instead of drm_err() (Philippe). * Collect tags from v1, as nothing substantial has changed. drivers/gpu/drm/stm/ltdc.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) base-commit: 542898c5aa5c6a3179dffb1d1606884a63f75fed